1. Field of the Invention
The present invention relates to a variable movement headrest arrangement for providing support to the head of an occupant of a vehicle upon vehicle impact.
2. Background Art
Improvements in safety mechanisms in the automotive industry continue to be made year after year. Such safety mechanisms include safety headrests. Example safety seat headrests can be found in Viano et al., U.S. Pat. No. 5,378,043, which is incorporated herein by reference. Such safety headrest mechanisms provide support to the head of a vehicle occupant during crash situations.
More specifically, upon rear impact of a vehicle, the occupant of the vehicle compresses into the vehicle seatback, as the head, neck, and torso move substantially in unison. There typically is greater compression in the torso and buttocks regions than in the shoulder region of the occupant. Thus, it has been a concern that the seatback may possibly deflect under the torso and buttocks load before the head and neck of the occupant contacts the headrest attached to the seatback.
Upon front impact of a vehicle, an occupant of the vehicle moves forward relative to the vehicle seatback. Upon contact with a front interior panel or a deployed air bag from the front panel, the occupant experiences rebound movement in a rearward direction. Similar to a rear impact situation as described above, the occupant in such a situation would then provide a rearward load into the seatback and compress into the vehicle seatback, as the head, neck, torso, and buttocks move substantially in unison. Thus, in a front impact it is also a concern that the seatback may possibly deflect under the torso load prior to the head and neck of the occupant contacting the headrest.
As a result, safety headrest mechanisms have been designed such that, upon rear impact, the occupant""s torso contacts an impact target of a vehicle seat with a rearward load or force. The impact target is operatively connected to a headrest cushion portion such that, upon the rearward load on the impact target, the headrest cushion portion moves forwardly toward the head of the occupant. The forward movement of the cushion portion in the crash situation lessens the gap which may exist between the head of the occupant and the headrest cushion portion, preventing or decreasing the risk of whiplash to the occupant.
However, it would be desirable to have the headrest arrangement move forward at a higher velocity to decrease the gap more quickly, but without contacting the occupant""s head while moving at the higher velocity.
It is an object of the present invention to provide a cost effective mechanism to support the head of an occupant of a vehicle upon vehicle impact.
In carrying out the above object, and other objects and features of the invention, a new vehicle seat and headrest arrangement for use with a seat having a seatback in a vehicle is provided. The vehicle seat and headrest arrangement comprises a headrest arrangement including a headrest, at least one impact target, and at least one of a guide member and a follower. The seatback has the other at least one of a guide member and follower. The guide member has a guideway and the follower engages the guideway of the guide member such that upon impact to the vehicle a rearward load by the occupant upon the impact target will cause the follower to engage the guideway in such a manner to cause the headrest to be moved in a first manner and a second manner to support the head of an occupant.
In a more specific embodiment, the guide member is a bushing having a cam configuration and the follower is a cam such that engagement of the cam and cam configuration together with the forward momentum of the headrest cause the headrest to move in a first manner and a second manner.
In another more specific embodiment, the guideway has a first guideway wall and a second guideway wall and the follower has a first follower portion and a second follower portion which engage the first guideway wall and second guideway wall respectively to cause the headrest to move in a first manner and a second manner to support the head of an occupant. The second guideway wall may have a first contact portion and a second contact portion and the second follower portion may have a first surface portion and a second surface portion such that upon impact to the vehicle, the first surface portion slidingly engages the first contact portion while the first follower portion slidingly engages the first guideway wall so as to cause the headrest to move in a first manner before the second surface portion slidingly engages the second contact portion as first follower portion continues to slidingly engage the first guideway wall so as to cause the headrest to move in a second manner. The first contact portion may have a relatively curved surface configuration, the second contact portion may have a relatively flat surface configuration, the first and second surface portions may have relatively flat surface configurations, the first guideway wall may have a relatively curved surface configuration, and first follower portion may have an arcuately-topped protrusion configuration.
In another more specific embodiment, the vehicle seat and headrest arrangement further includes a movement-allowing connector connected between the headrest arrangement and the seatback.
In another more specific embodiment, the seatback may have a seatback frame having side members and the movement-allowing connector may be at least one link pivotally connected between the side members of the seatback frame and the impact target. The link may be connected to the side member along a pivot axis offset relative to the impact target such that a rearward force of an occupant on the impact target will tend to cause the impact target to move in a generally rearward and upward direction and move the headrest arrangement
In another more specific embodiment, the vehicle seat and headrest arrangement further includes a biasing member operatively associated with the seatback and the headrest arrangement which tends to bias the headrest against movement in a first and second manner.
In another more specific embodiment, movement in a first manner is movement on a first trajectory and at a first forward velocity and movement in a second manner is movement on a second trajectory and at a second forward velocity which is less than the first forward velocity.
The vehicle seat and headrest arrangement for use with a seat having a seatback in a vehicle may also comprise a headrest arrangement including a headrest and a headrest extension, the headrest extension having at least one of a guide member and a follower and an impact target located below the at least one of a guide member and a follower. A seatback frame of the seatback has an upper cross frame member. The upper cross frame member has at least one of a guide member and follower, the guide member has a guideway and the follower slidingly engaging the guideway of the guide member such that upon impact to the vehicle a rearward load by the occupant upon the impact target will cause the follower to be slidably guided by the guideway such that the headrest is moved in a first manner and a second manner.
In a more specific embodiment, the vehicle seat and headrest arrangement further includes a movement-allowing connector connected between the headrest arrangement and the seatback frame. The movement-allowing connector may be at least one link pivotally connected between the side members of the seatback frame and the impact target. The link may be connected to the side member along a pivot axis offset relative to the impact target such that a rearward force of an occupant on the impact target will tend to cause the impact target to move in a generally rearward and upward direction and move the headrest arrangement.
In another more specific embodiment, the vehicle seat and headrest arrangement further includes a biasing member operatively associated with the seatback and the headrest arrangement which tends to bias the headrest against movement in a first and second manner.
In another more specific embodiment, the guide member is fixedly attached to the seatback frame and has a first guideway wall and a second guideway wall and the follower is fixedly attached to the headrest extension and has a first follower portion and a second follower portion which slidingly engage the first guideway wall and second guideway wall respectively. The second guideway wall may have a first contact portion and a second contact portion and the second follower portion may have a first surface portion and a second surface portion such that upon impact to the vehicle the first surface portion slidingly engages the first contact portion while the first follower portion slidingly engages the first guideway wall so as to cause the headrest to move in a first manner before the second surface portion slidingly engages the second contact portion as first follower portion continues to slidingly engage the first guideway wall so as to cause the headrest to move in a second manner. The first contact portion may have a relatively curved surface configuration, the second contact portion may have a relatively flat surface configuration, the first and second surface portions may have relatively flat surface configurations, the first guideway wall may have a relatively curved surface configuration, and first follower portion may have an arcuately-topped protrusion configuration.
In another more specific embodiment, movement in a first manner is movement on a first trajectory and at a first forward velocity and movement in a second manner is movement on a second trajectory which is generally more upwardly than the first trajectory and a second forward velocity which is less than the first forward velocity
The vehicle seat and headrest arrangement for use with a seat having a seatback in a vehicle may also comprise a headrest arrangement including a headrest and a headrest extension, the headrest extension having a follower fixedly connected to the headrest extension and an impact target located below the follower. A seatback frame of the seatback has side members and an upper cross frame member. The upper cross frame member has a guide member fixedly connected to the cross frame member through which the follower extends and the guide member has a guideway. The follower slidingly engaging the guideway of the guide member such that upon impact to the vehicle a rearward load by the occupant upon the impact target will cause the follower to be slidably guided by the guideway such that the headrest is moved in a first manner and a second manner.
In a more specific embodiment, the vehicle seat and headrest arrangement further includes a movement-allowing connector and a biasing member, the movement-allowing connector being at least one link pivotally connected between the side members of the seatback frame and the impact target and the link being connected to the side member along a pivot axis offset relative to the impact target such that a rearward force of an occupant on the impact target will tend to cause the impact target to move in a generally rearward and upward direction and move the headrest assembly, the biasing member being operatively connected between the seatback frame and the headrest arrangement so as to bias the headrest against movement in a first and second manner.
In another more specific embodiment, movement in a first manner is movement on a first trajectory and at a first forward velocity and movement in a second manner is movement on a second trajectory which is generally more upwardly than the first trajectory and a second forward velocity which is less than the first forward velocity.
In another more specific embodiment, the second guideway wall has a first contact portion and a second contact portion and the second follower portion has a first surface portion and a second surface portion such that upon impact to the vehicle, the first surface portion slidingly engages the first contact portion while the first follower portion slidingly engages the first guideway wall so as to cause the headrest to move in a first manner before the second surface portion slidingly engages the second contact portion as first follower portion continues to slidingly engage the first guideway wall so as to cause the headrest to move in a second manner. The first contact portion may have a relatively curved surface configuration, the second contact portion may have a relatively flat surface configuration, the first and second surface portions may have relatively flat surface configurations, the first guideway wall may have a relatively curved surface configuration, and first follower portion may have an arcuately-topped protrusion configuration.